A 'retraction' method for learned navigation in unknown terrains for a circular robot

Because of the number of setups directly affects the fixturing, tolerancing, and machining time, an algorithm has been developed to determine the minimum number of setups required for producing the part. The algorithm first attempts to fathom the possibility of achieving the target part from a single setup. This step involves exploring the possibility of achieving the target part from a single machining direction in the set of candidate machining directions defined by the enclosing object faces. If multiple setups is inevitably required, then the algorithm searches from the minimum number of setups to achieve the target part by enumeration. As an illustration, consider the part shown in Fig. 14(a). This part is machinable from the enclosing object MEB since all the part faces are visible. The system then determines that at least two machining setups are required to achieve the finished part requirement. The " removal volume " formed by the union of valid prisms and residues from each setup is subsequently constructed as shown in Fig. 14(b). The prisms provide depth information for material removal from the part in the form of z = f (x , y) where z is the depth from the enclosing object (or raw stock) face, and (x, y) are the coordinates of a point on an enclosing object face. Using this depth information with linear interpolation techniques, cutting strategies and a tool path can be derived (see Fig. 14(c)). The generated enclosing object and the orientation of the enclosing object face can be used as a reference for the raw stock and fixture positioning, respectively. V. CONCLUSIONS We have presented a machinability test that determines whether a given part can be machined from a certain set of machining directions , such as those obtained from the convex hull, the minimum enclosing box, or by the augmentation of these surfaces. The analysis of machinability focuses only on polyhedral parts. However , curved surfaces can also be incorporated via polygonal faceting. This provides an automatic method for segmenting the surface into portions that need to be accessed from different directions. A. Parkinson, " The use of solid models in BUILD as a database for NC machining, " in Software for Discrete Manufacturing, J. P. __ 699 r91 U01 machining process/programming language, " in Proc. IEEE Int. Abstract-We consider the problem of learned navigation of a circular robot R , of radius 6 (B 0), …